The present invention relates to electrical enclosures having boxes and trim panels and particularly tabs for supporting and aligning the enclosure trim panel with the enclosure box.
Electrical enclosures, such as low-voltage, circuit protection load centers, often have a box with an open side for access to the interior of the enclosure that is installed between wall studs of a building partition, so that the open side of the box is flush with the partition outer surface. The enclosure is in turn covered by a trim panel which is of generally planar construction for flush fit with the box and partition. The trim panel is attached to the box with fasteners, such as screws, which pass through holes formed in the trim panel. The trim panel generally has a hinged access door which allows user manipulation of circuit breaker actuation handles located in the panel.
When installing a trim panel on an electrical enclosure box, the electrician is faced with the problem of attempting to align fastener holes formed in the trim panel with corresponding fastener holes located in the box. The trim panel is often constructed of stamped sheet metal and often weighs between 2 and 10 pounds. During installation of the trim panel, the electrician is attempting to line a generally flat, heavy cover with a flat wall surface, while trying simultaneously to align fastener holes in the trim panel with the box fastener holes. Trim panel installation is often a time-consuming and frustrating experience for the electrician.
Past attempts to remedy difficulties in installing trim panels over electrical enclosure boxes have led to limited success. One known past solution has been to have a first electrician hold the trim cover and assume most of the responsibility for bearing its weight, while a second electrician visually aligns the trim cover holes with the box holes and performs precision alignment. Upon alignment, one of the electricians then installs the trim panel fasteners. This known solution doubles the number of highly-paid tradesman necessary to install the trim panel.
Another known attempt to solve the trim panel installation alignment problem is to utilize one or more locating pins, having a diameter smaller than the trim panel fasteners. The locating pins are separately inserted in one or more of the trim panel fastener holes and positioned in the corresponding box fastener hole. To practice this solution, the electrician has to keep and maintain a separate set of alignment pins, which can be easily lost. Also, the alignment pin must be removed before a fastener ultimately can be placed in the pin location, which increases the number of steps necessary to install the trim panel.
Another known solution for aligning trim panels is to utilize a fastener having a stepped tip with a diameter less than the diameter of the fastener threads. This type of stepped fastener has an integral alignment pin. However, during installation of at least the first two stepped fasteners, the corresponding holes in the trim panel and box for receipt of the fastener have to be aligned visually or aligned by tactile feel as the electrician wiggles the fastener in the trim panel fastener hole with his fingers as he attempts to engage the box fastener holes. Also, during installation of at least the first two stepped fasteners, the electrician still must hold up the weight of the trim panel and perform at least the gross alignments of the trim panel and box screw holes, so that the step fastener can be located in the holes and maneuvered to its final alignment position.
U.S. Pat. No. 4,517,623 shows trim supports secured to the rear face of a trim ring 14. The trim supports are described as fitting between lateral sidewalls of the enclosure box which engage the edge of the bottom sidewall of the enclosure box. It is stated in the patent that the trim supports allow the installer to rest the trim panel on the enclosure box's lower edge to support the assembly while it is being secured in place. However, the supports of the '623 patent do not fully support the trim panel weight and maintain alignment between the trim panel and box fastener holes, because the trim panel can tip away from the box about a rocking axis established by contact of the supports with the box lower edge.
It is an object of the present invention to create an electrical enclosure support which allows for vertical and horizontal alignment of the trim panel with the box, so that the trim panel fasteners can be installed by a single person.
It is a second object of the present invention to create a trim panel support tab that supports the weight of the trim panel until the electrician can perform final alignment of the trim panel fastener holes with those of the box.
It is another object of the present invention to create a trim panel support tab that does not block trim panel fastener holes during panel and pan alignment, while fully supporting the trim panel weight.
It is an additional object of the present invention to create a trim panel supporting tab that requires no additional tools or separate parts in order to align and fully support the weight of the trim panel.